Evaluation of new conducting polymeric membrane based on sulfonation of compatibilized NR/EPDM blend

In this study, research was undertaken to obtain new conducting polymer blend membrane based on compatibilized natural rubber/ethylene–propylene–diene monomer (NR/EPDM) by using different compatibilizers. To utilize them as membranes in polymer electrolyte membrane fuel cells, the blend membranes become conducting by sulfonation reaction, which inserts SO3H groups into the macromolecular chain. The polymer blend membrane ratio (50/50), which was compatibilized by polyacrylonitrile compound was selected among the entire blend studied (A6), with the aim of determining its conductivity and water and methanol permeabilities. The degree of compatibility of NR/EPDM blend was improved by the use of polyacrylonitrile compounds as compatibilizers. The effect of these compounds on the compatibility of blend was evaluated by ultrasonic spectroscopy and differential scanning calorimetry, DSC. It was found that a good compatibility has been achieved by using polyacrylonitrile because of the nitrile groups. When the polymer blend membrane (A6) was sulfonated with SO3H groups good perspectives were shown regarding the methanol and water permeabilities and physical properties comparing to the commercial Nafion one. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3804–3812, 2007